Teledyne Princeton Instruments PI-MAX 3, System Manual

Page: 199 / 250

Appendix A Technical Specifications 199
Sensitivity
Variable intensifier gain adjustment (via software) allows sensitivities from 1-80
counts/photoelectron for Gen II and 1-200 counts/photoelectron for Gen III.
Some phosphor choices may result in lower values. Gain adjustment range is
1-100.
Gating ON/OFF Ratio
Visible (550 nm):
• 5 x 10
6
:1 typical.
UV (250 nm):
• 10
4
:1 with photocathode gating only;
• 10
6
:1 with supplemental MCP bracket pulsing typical.
Response Linearity
Linearity is difficult to predict in ICCD systems, especially at high frame rates.
Most intensifiers cannot generate sufficient light in a single gate to achieve full
scale illumination, or even approach it. Generally, it takes a few milliseconds for
an intensifier to recover from a single gate event (if the charge output is
significant). Good linearity is observed when the light intensity is low and the
signal is built up over a large number of exposures or over a long exposure.
Poor linearity is observed when one attempts to get large signal amplitude from
a single short exposure. This is a general property of MCP image intensifiers, not
just of Teledyne Princeton Instruments ICCDs.
Photocathode Dark Charge (EBI)
Red-blue enhanced, < 5 counts/pixel-second;
Red-enhanced, < 15 counts/pixel-second.
Phosphor Decay
• 3 ms P43 standard
• 2

s P46 phosphor is optional
Phosphor Emission Spectra
See Figure A-1
• P43 = Gd2O2S:Tb
• P46 = Y3Al5O12:Ce
Figure A-1: Typical Phosphor Emission Spectra
Wavelength (nm)
Spectr
al Emission (W/W/nm)
44
11
-0
12
9_
0
12
1